I'm working on a basement renovation and I want to install heated floors in my bathroom. The problem is, the city says I need to insulate my concrete slab to an R-value of 10, but I only have 1" of space to work with before I add the tile. I've been considering products like Schluter-Ditra and WarmUp, but I'm not sure if they provide enough insulation. Does anyone have suggestions for how to meet code while keeping my bathroom floor level with the rest of the space?
3 Answers
It seems a bit overkill for a bathroom to require such a high insulation value. If you only heat the floor, that shouldn't lose much heat. An inch of polyiso might actually be more than enough. It's worth pushing back on the city about it!
Getting to R-10 in just an inch is going to be tough. You might need to look at products like polyiso, but you'll probably end up needing about 2 inches for that insulation value. Just check if polyiso is suitable for under tile before you commit to it!
2 inches would drop the ceiling too low though. Am I just out of luck for my heated floor idea?
Honestly, if it were me, I'd consider ripping out the floor. A small bathroom isn't that hard to work with, and then you could add foam insulation under the concrete when you pour it back in. Just make sure you plan ahead to keep everything level!
If I bust out the floor, what comes next? Just foam under the new concrete? I've done it once for plumbing, but not looking forward to another round.
I hear you! The rest of the basement has forced air heat, so this is just for the bathroom floor. Let's see how this plays out!